(CNN) -- At a time when gas prices are at an all-time high, Americans have curtailed their driving at a historic rate.

Americans are not driving as much as they did a year ago as gas prices skyrocket.

The Department of Transportation said figures from March show the steepest decrease in driving ever recorded.

Compared with March a year earlier, Americans drove an estimated 4.3 percent less -- that's 11 billion fewer miles, the DOT's Federal Highway Administration said Monday, calling it "the sharpest yearly drop for any month in FHWA history." Records have been kept since 1942.

According to AAA, for the first time since 2002, Americans said they were planning to drive less over the Memorial Day weekend than they did the year before.

Tracy and Adam Crews posted on iReport that their annual Memorial Day weekend has traditionally involved camping and fishing.

"Well, due to the continual rise in gas, we felt our only recourse was to nix the idea this year and stay home" in Jacksonville, Florida, they wrote.

Instead, the couple said they "decided to camp out in the backyard. We set the tent up, just finished installing our above ground pool, and cleaned up the grill. ... We have ourselves a campsite! It's been a blast!"